Asymptotic power of likelihood-ratio tests for detecting quantitative trait loci using the COGA data

Jeff T. Williams, John Blangero

    Research output: Contribution to journalArticle

    13 Scopus citations


    We investigated the asymptotic power of the likelihood-ratio test for detecting linkage to a quantitative trait locus (QTL) using the data set from the Collaborative Study on the Genetics of Alcoholism (COGA). Assuming a total trait heritability of 50% as determined for the COGA Cz P300 phenotype, we determined the minimum QTL heritability required at each point in the genome to achieve 80% power to detect linkage with a lod of 3.0. We find that there are regions of the genome where it is not possible to detect a QTL of any effect with 80% power, and that the overall minimum detectable QTL heritability for the COGA data is 0.35-0.40.

    Original languageEnglish (US)
    Pages (from-to)S397-S402
    JournalGenetic epidemiology
    Issue numberSUPPL. 1
    StatePublished - Dec 10 1999



    • Linkage analysis
    • Noncentral chi-squared
    • Statistical genetics
    • Variance component

    ASJC Scopus subject areas

    • Epidemiology
    • Genetics(clinical)

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